Reel end signal for motion picture projectors



Dec. 13, 1938. o. HEMMINGSON 2,140,227

REEL END SIGNAL FOR MOTION PICTURE PROJECTORS Filed Jan; 19, 1958 2-Sheets-Sheet l Dec. 13, 1938.

REEL

o. HEMMINGSON END SIGNAL FOR MOTION PICTURE PROJECTORS Filed Jan. 19, 1938 2 Sheets-Sheet 2 Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE REEL END SIGNAL FOR MOTION PICTURE PROJECTORS 3 Claims.

This invention relates to a reel end signal for motion. picture projectors, the general object of the invention being to provide means for actuating a signal when the film nears the end of the picture, so that the operator will know that the end is approaching.

The invention also consists in certain other features of construction, combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claims.

In describing the invention in detail reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which:-

Fig. 1 is an elevation of a magazine of a projector, with the invention in use thereon.

Fig. 2 is a top plan view of Fig. 1.

Fig. 3 is a vertical sectional view through Fig. 1.

Fig. 4 is a section on line 4-4 of Fig. 2.

Fig. 5 is a view of the weighted number and the bell clapper or hammer.

Fig. 6 is a section on line 66 of Fig. 2.

In these drawings, the numeral I indicates the magazine of a projector, which has one side closed by the door 2, hinged to the magazine at 3 and having a latch 4. The opposite side of the 30 magazine has the hub 5 connected therewith, through which passes the shaft 6, having the spring 1 thereon, adjusted by the nut 8, for applying tension to the film, in the usual manner.

In carrying out my invention I attach an arm 9 to the hub 5 by means of the clamping block I0, the bolts H and the winged nuts I2, so that the arm may be adjusted on the hub. A post I3 is connected to the outer end of the arm and supports a bell M. A shaft I5 has one end journalled in the outer side of the arm, adjacent the center thereof, and a metal strip I6 is connected to the outer end of the shaft and extends upwardly therefrom, as shown in Fig. 1. The member l6 has a weight I! connected to 45 its upper end and a bell clapper or hammer I8 is also connected to the outer end of the shaft l5 and extends upwardly in spaced relation to the member 16. A cam I9 is fastened to the outer end of the shaft 6 by the nuts and 8 and said cam is formed of a circular washer having one side out off to providea straight side and a rounded corner, as shown in Fig. 1. This cam will engage the member 16 as it rotates with the shaft 6 but until the film nears its end, the 55 parts are rotating so slowly that the cam will only move the member IS a small amount, as shown in full and left hand dotted lines of Fig. 1. However, when the film is nearing its end, the parts will be rotating faster and this more rapid rotation of the cam will throw the member 5 5 over to the right hand dotted line position of Fig.

1 and thus the hammer I8 will strike and ring the bell, so that the operator will know that the end of the film is near.

In order to reset the parts after the reel has 10 been removed, I fasten an end of an arm 2| to the hinge pin 3 and pivot a rod 22 to the other end of the arm, the rod passing through a guide 23 on the arm 9. Thus when the door is opened, the arm 2| will slide the rod 22 through the guide 15 23 and cause the rod to strike the depending part l5 of shaft 15 and thus swing the member I6 and the bell hammer over tothe full line position of Fig. l and thus the parts will be in set position ready for the next film.

By adjusting the arm. 9 on the hub the point at which the signal will be given can be regulated. For instance, if the arm is raised the alarm will be given later than it will be if the arm is lowered.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is tobe understood that changes may be made in the construction, combination and ar- 30 rangement of the several parts, provided such changes fall within the scope of the appended claims.

What I claim and desire to protect by Letters Patent is:

1. In combination with a magazine of a projector, including its hub and tension shaft, an arm connected with the hub, a bell supported from the arm, an upright supported from the arm for rocking motion, a hammer movable with the 40 upright for engaging the bell and a cam on the shaft for engaging the upright and for swinging the same to a position where the hammer will engage the bell when the shaft is rotating rapidly by the film nearing its end.

2. In combination with a projector magazine including its hub and tension shaft, an arm adjustably connected with the hub, a cam attached to the shaft, an upright member pivotally supported from the arm and engaged by the cam, 50 a signal carried by the arm, means carried by the upright member and actuating the signal when the upright member is swung to a great extent by the rapid rotation of the shaft, due to the film nearing its end.

3. In combination with a projector magazine including a door, hub and tension shaft, an arm adjustably connected with the hub, a cam attached to the shaft, an upright member pivotally supported from the arm and engaged by the cm, a signal carried by the arm, means carried by the upright member and actuating the signal when the upright member is swung to a great extent by the rapid rotation of the shaft, due to the film nearing its end, and means for resetting the upright member when the door 01' the magazine is opened.

ORVIN HEMMINGSON. 

